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Gradient boosting is a machine learning technique based on boosting in a functional space, where the target is pseudo-residuals instead of residuals as in traditional boosting. It gives a prediction model in the form of an ensemble of weak prediction models, i.e., models that make very few assumptions about the data, which are typically simple ...
XGBoost works as Newton–Raphson in function space unlike gradient boosting that works as gradient descent in function space, a second order Taylor approximation is used in the loss function to make the connection to Newton–Raphson method. A generic unregularized XGBoost algorithm is:
LightGBM, short for Light Gradient-Boosting Machine, is a free and open-source distributed gradient-boosting framework for machine learning, originally developed by Microsoft. [4] [5] It is based on decision tree algorithms and used for ranking, classification and other machine learning tasks. The development focus is on performance and ...
It provides a gradient boosting framework which, among other features, attempts to solve for categorical features using a permutation-driven alternative to the classical algorithm. [7] It works on Linux , Windows , macOS , and is available in Python , [ 8 ] R , [ 9 ] and models built using CatBoost can be used for predictions in C++ , Java ...
scikit-learn (formerly scikits.learn and also known as sklearn) is a free and open-source machine learning library for the Python programming language. [3] It features various classification, regression and clustering algorithms including support-vector machines, random forests, gradient boosting, k-means and DBSCAN, and is designed to interoperate with the Python numerical and scientific ...
Appearance based object categorization typically contains feature extraction, learning a classifier, and applying the classifier to new examples. There are many ways to represent a category of objects, e.g. from shape analysis , bag of words models , or local descriptors such as SIFT , etc. Examples of supervised classifiers are Naive Bayes ...
In the gradient descent analogy, the output of the classifier for each training point is considered a point ((), …, ()) in n-dimensional space, where each axis corresponds to a training sample, each weak learner () corresponds to a vector of fixed orientation and length, and the goal is to reach the target point (, …,) (or any region where ...
It is shown that this is directly equivalent to decreasing the learning rate in gradient boosting = + (), where decreasing improves the regularization of the boosted classifier. The theory makes it clear that when a learning rate of γ {\displaystyle \gamma } is used, the correct formula for retrieving the posterior probability is now η = f ...